I'm working on a curious project here. I tried searching the forum but I couldn't find any similar topics, so hopefully this isn't a duplicate, but if it is, please point me in the right direction. I've got a switching power supply from an Xbox 1.4 that is on the fritz. I just got it from someone that said it doesn't turn on. It was extremely dirty (roaches, to be exact) and I pieced it apart and ran all the electronic and plastic pieces (not mechanical or optical) through a short cycle in the dishwasher, then promptly dried it all off with compressed air. Visually, all the components are now as good as new. No leaking or bulged capacitors, no discolored ICs, no burn marks on the PCB, no blown traces - everything, visually, is absolutely perfect... well, except the annoying white "glop" all over the place from the factory...
However, the original problem still seems to remain. The power supply is almost completely dead. I've got a bit of experience with electronics - I've fixed a few things, but just the same, I've been unable to fix a large stack of things as well (that I hope one day to understand how to fix). Armed with a cheap $3 digital multimeter from Harbor Freight, I've found that the initial stages of the AC filtering seem to work fine. The large (250v/470µF) filtering capacitor charges up to 166.4 volts (line voltage is 120v/60hz). But that's where the line stops.
I checked the standby (3.3v) transformer for AC output (on the low side) while plugging the power supply in to line, and I got nothing. Zero volts. All the low side capacitors are also showing 0.00 volts. Everything is dead straight from the get-go.
I've also got another power supply that exhibits exactly the same behavior. It was working just fine until I broke apart the high and low sides to try diagnosing another power supply... with, you guessed it... that same problem as well. After re-assembling and resoldering the components, the power supply no longer functions at all. And I've got another few PC ATX power supplies in the closet that, you guessed it, do the same thing. So to be able to understand why this happens on this power supply would help me fix a LOT of things.
Armed with just a cheap digital multimeter, what can I do to, perhaps, fix this?
edit: One minute, I'll try looking up some information about the Xbox power supply for those curious.
edit: Crap, there's no technical information available. I coulda sworn I made this edit days ago though...
However, the original problem still seems to remain. The power supply is almost completely dead. I've got a bit of experience with electronics - I've fixed a few things, but just the same, I've been unable to fix a large stack of things as well (that I hope one day to understand how to fix). Armed with a cheap $3 digital multimeter from Harbor Freight, I've found that the initial stages of the AC filtering seem to work fine. The large (250v/470µF) filtering capacitor charges up to 166.4 volts (line voltage is 120v/60hz). But that's where the line stops.
I checked the standby (3.3v) transformer for AC output (on the low side) while plugging the power supply in to line, and I got nothing. Zero volts. All the low side capacitors are also showing 0.00 volts. Everything is dead straight from the get-go.
I've also got another power supply that exhibits exactly the same behavior. It was working just fine until I broke apart the high and low sides to try diagnosing another power supply... with, you guessed it... that same problem as well. After re-assembling and resoldering the components, the power supply no longer functions at all. And I've got another few PC ATX power supplies in the closet that, you guessed it, do the same thing. So to be able to understand why this happens on this power supply would help me fix a LOT of things.
Armed with just a cheap digital multimeter, what can I do to, perhaps, fix this?
edit: One minute, I'll try looking up some information about the Xbox power supply for those curious.
edit: Crap, there's no technical information available. I coulda sworn I made this edit days ago though...
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